1. Field of the Invention
The present invention relates to a control box having at least one electric device which is cooled down by at least one fan unit.
2. Description of the Related Art
A control box is equipped with one or more fan units for cooling down heated electric devices which are put therein. For durability of the fan units, they must be replaced or maintained, regularly or when one of them breaks down. Generally, the control box comprises a case with a door in the front portion so as to assemble/disassemble the electric devices and be operated therefrom. The fan units are located in back of the electric devices so that an operator can replace the fan units with new ones from the rear portion of the case. The rear portion of the case, however, may cling to a machine or a wall of the factory, whereby the control box must be moved in order to replace the fan units.
Japanese Patent Laid-open Publication No. 2000-340975, the prior art to resolve the above-mentioned problem, discloses a fan unit connecting the fan with one portion of the board via link mechanism. With the link mechanism, when the fan unit is inserted into the case from its front, the fan is turned to the back of the electric devices. However in the prior art, since the path of the fresh air is not separated from the path of the heated air in the case, the heated air through the electric devices, for example, may enter an intake of the fans so as to cool down inefficiently. For cooling down efficiently, since it is necessary to locate the fans in back of a plurality of the electric devices, a plurality of the fan units should be inserted into the box. Further, it is necessary to make enough spaces for turning and placing the fans. Furthermore, the link mechanisms for turning the fans are complicated so that manufacturing the fan units needs a lot of process.